Particle-based Co-Delivery of HIV Immunogens as Next-Generation HIV Vaccines: A major focus of HIV vaccine research has been the development of immunogens that elicit broadly neutralizing antibody responses targeting the envelope protein (Env). While the field has predominantly focused on immunogen design and soluble antigens, the targeted and controlled delivery of antigens and optimal antigen-adjuvant formulations has not received much attention and is a gap in the HIV field that needs to be addressed. Lipid- and polymer-based nanoparticle platforms have been shown to induce HIV-specific antibody and cellular immune responses in animal studies. HIV immunogens delivered via particle-based modalities may elicit better and improved humoral and cellular immune responses. The goal of this contract is to engineer novel HIV gp41 ectodomain antigens and to optimally display the epitopes in the immunogenic VesiVax platform.